The widespread promulgation of emissions regulations across all categories of emitting sources presents unique challenges to residential appliances. Unlike commercial/industrial combustion sources which utilize and adapt decades of utility-scale emissions technologies in response to environmental regulations, residential appliances with atmospheric burners require totally different strategies for achieving significant emissions reductions.
The difficulties associated with developing low emissions atmospheric burner technology has led many manufacturers to adopt forced draft, fully premixed combustion methods. Although this is an effective approach to reducing NO.sub.x and CO emissions, such a solution is very expensive compared with the atmospheric burners they replace. Thus, the use of atmospheric or induced draft technology, when made feasible, can provide a competitive advantage over the present "forced draft" technologies. At the same time, low emissions atmospheric burners can serve as a bridge between current and future heat exchanger designs.
Ceramic foam burners in a forced draft, fully premixed radiant mode have been used in industrial heat treating and drying operations. Examples of such industrial burners will be found in Morris U.S. Pat. No. 4,889,481 and Singh U.S. Pat. No. 5,174,744. However, ceramic foam has not been used for atmospheric, or induced draft, low emissions burners.